A mãe guardou a fralda e o babador na bolsa antes de sair com a bebê.

Guardou is the preterite form of guardar, for ele/ela/você.

• guardar = to keep, store, put away
• guardou = she put away / she stored / she kept

In this sentence, it describes a completed action in the past: the mother put the diaper and bib in the bag.

This is very common in Brazilian Portuguese:

• Ela guardou as chaves. = She put away the keys.
• Ele guardou o dinheiro. = He put away the money.

Not exactly word-for-word, but it is a very natural choice.

In context, guardou suggests:

• putting something away
• storing something
• placing something somewhere for later use

So in this sentence, it works like put away or simply put in English.

A close alternative would be:

• A mãe colocou a fralda e o babador na bolsa...

But the nuance is slightly different:

• colocou = put/placed
• guardou = put away/stored

Portuguese uses definite articles much more often than English.

In English, you might say:

• Mother put diaper and bib in the bag

But in Portuguese, it is more natural to say:

• A mãe guardou a fralda e o babador na bolsa...

Articles often appear before:

• nouns in general
• family roles
• concrete objects
• people being referred to in a specific context

So even when English might leave out the, Portuguese often keeps a/o/as/os.

Na is a contraction of:

• em + a = na

So:

• na bolsa = in the bag

Other common contractions:

• no = em + o
• nos = em + os
• nas = em + as

Examples:

• no carro = in the car
• na mochila = in the backpack

After the preposition de, Portuguese normally uses the infinitive.

So:

• antes de sair = before leaving / before she left to go out

You do not use a past form like saiu after de here.

This pattern is very common:

• antes de comer = before eating
• depois de estudar = after studying
• sem falar = without speaking

By default, it is understood to be the same subject as the main verb.

So in:

• A mãe guardou... antes de sair...

the understood meaning is:

• The mother put the diaper and bib in the bag before she went out.

Portuguese often leaves that unstated when it is clear from context.

If you wanted a different subject, you would usually need a different structure, for example:

• A mãe guardou a fralda antes de a bebê sair. = The mother put away the diaper before the baby left.

Because bebê can be used for either a male or female baby, and the article shows the gender of the specific child being talked about.

• o bebê = the baby boy / the baby
• a bebê = the baby girl / the baby

In this sentence, a bebê shows that the baby is female.

This is something English speakers often notice because the noun itself does not change, but the article does.

Yes, in Brazilian Portuguese it is written bebê with an acute accent.

The accent shows the stressed final syllable:

• be-BÊ

In European Portuguese, you may also see bebé, but in Brazil the normal spelling is bebê.

Because Portuguese often leaves out possessives when the relationship is obvious from context.

Here, if we already know we are talking about the mother and the baby she is with, a bebê is enough.

So Portuguese often prefers the simpler version:

• A mãe saiu com a bebê.

instead of:

• A mãe saiu com sua bebê.

Also, possessives in Portuguese can sometimes sound more marked or more specific than in English.

Yes, absolutely.

• guardou = put away, stored
• colocou = put, placed

So:

• A mãe guardou a fralda e o babador na bolsa...
• A mãe colocou a fralda e o babador na bolsa...

Both are natural, but they are not identical in tone:

• guardou suggests putting the items away in an organized or practical way
• colocou is more neutral and simply means she placed them there

These are just grammatical genders of the nouns, and they do not always follow a logical pattern.

• a fralda = feminine
• o babador = masculine

Sometimes endings help:

• nouns ending in -a are often feminine
• nouns ending in -o are often masculine

But this is only a tendency, not a perfect rule.

For these words, you should simply learn them together with their articles:

• a fralda
• o babador

That is the best habit in Portuguese.

Yes. Portuguese allows that very naturally.

You can say:

• A mãe guardou a fralda e o babador na bolsa antes de sair com a bebê.
• Antes de sair com a bebê, a mãe guardou a fralda e o babador na bolsa.

Both are correct.

The difference is mainly one of emphasis:

• the original version emphasizes the action first
• the version starting with antes de sair... emphasizes the time frame first

Mãe has a nasal sound that English speakers often find tricky.

A rough guide:

• it sounds something like myng or mahyng, but very short and nasalized

Important points:

• the ã is nasal
• the final e is not pronounced like a full English ee
• the whole word is basically one strong syllable

A useful strategy is to listen and imitate native audio, because nasal vowels are hard to learn from spelling alone.

It can mean both, depending on context.

• sair = to leave
• sair = to go out

In this sentence, antes de sair com a bebê most naturally means:

• before going out with the baby

But in other contexts it could simply mean:

• leaving
• going out
• coming out

Examples:

• Ela saiu de casa. = She left the house.
• Eles saíram à noite. = They went out at night.